Glossary
45
TR area A data area used to store execution conditions so that they can be reloaded
later for use with other instructions.
UM area The memory area used to hold the active program, i.e., the program that is
being currently executed.
Unit In OMRON PC terminology, the word Unit is capitalized to indicate any prod-
uct sold for a PC System. Though most of the names of these products end
with the word Unit, not all do, e.g., a Remote Terminal is referred to in a col-
lective sense as a Unit. Context generally makes any limitations of this word
clear.
unit number A number assigned to some Link Units and Special I/O Units to facilitate
identification when assigning words or other operating parameters to it.
watchdog timer A timer within the system that ensures that the scan time stays within speci-
fied limits. When limits are reached, either warnings are given or PC opera-
tion is stopped depending on the particular limit that is reached.
word In digital circuits, a group of bits. Usually a word consists of four, eight, or
sixteen bits. In C-series PCs, a word consists of sixteen bits. Words can be
used to store data, or they can be used for I/O.
work bit A bit in a work word.
To Next Page
Loading...
